Comparison of two linearization methods for optimal attitude maneuver of a non-linear flexible spacecraft

Abstract

In this paper, we consider the optimal attitude maneuver design for a non-linear flexible spacecraft with vibrating solar arrays. Two different linearization methods for the non-linear system are compared in this study. One is the recursive approximating sequence approach (RASA) to design a time-varying linear quadratic regulator (LQR) for the non-linear system and the other is to design a LQR by linearizing the non-linear system at each locally ‘frozen’ state in any sufficient small sphere along the trajectory. Numerical simulation shows that the later approach gives good design results quickly by scanning the time axis only one time. The RASA method may scan the time axis several times to get a good approach. Moreover, both linearization methods give satisfying control results in attitude maneuver and vibration suppression control for the non-linear flexible spacecraft.